See the sheer block size that would need to be implemented if you do the maths, and you see the magnitude of the problem.
i agree with some of the things you say but i am not yet convinced about either one of the solutions that are being proposed.
things are never as easy as just increase the block size and be done with it. increase by how much? the 8 MB of BCH? if we assume your numbers are correct that is 8*7=56 tx/sec that is still nowhere near 2000.
so what will we gain with that kind of increase? we just made running a full node 8 times harder.
i say on chain scaling is needed but i ask myself by how much? we can not have 500 MB blocks which is nearly 2000 tx/sec
that is where Lightning Network comes in. although that is less centralized than on-chain scaling but it is a solution to get that much tx/sec.
You see i can agree with this statement as well, which is why i had mentioned about some 'serious thinking and implementation' as larger blocks is not the 'best' solution either, BCH being a band-aid in the same way to the problem you talk about.
There is a careful balance to be struck, and I will admit, I have little clue as to what could be the best solution, simply increasing block size to approach that level isn't viable for the reasons we both stated, off-chain solutions have their own problems but are a potential possibility, like the lightning network.
I am unsure how this will play out in the long term, of course and that is if BTC is to be used as a currency, not a 'store' of value, in which case smaller blocks will suffice. Basically its picking the road it will go down.
Most of the endless 'bitcoin forks' have not put enough effort into this problem, but are merely an attempt to play games with money, Bitcoin Gold proposed ASIC resistance, yet had an insane premine
It is curious to see how this problem will be solved, it is no easy problem to solve. Ethereum will have the same problem re. how many smart contracts can run as they all use the entire network nodes to execute each piece of code.
The blockchain has changed the world, now it needs to scale
Often backlogs of transactions are 'caught up' during quiet times, but when used heavily daily, 'quiet times' may become non-existent and thus there would be a constant 'defect'